[KPhotoAlbum] Cycles in member maps
thsuut at utu.fi
Wed Apr 4 16:51:11 BST 2007
On 2007-04-04 Wednesday 17:41, Tero Tilus wrote:
> 2007-04-04 16:02, Tuomas Suutari:
> > I've been thinking to deny cycles in KPhotoAlbum's member maps.
> Very good idea.
> Thinking a little... It looks like the underlying concept of these
> "member maps" is set theory and "A is member of B" is to say A is a
> subset of B (yes, subset, not member).
Yep, that's a good analogy. And it works fine also when some item
belongs to two or more membergroups.
D < B, B < A, D < C, C < A
(Using following notation: X < Y means X is a subset of Y)
Or same as a graph:
/-> B -\
A -| |-> D
\-> C -/
Those could be useful and I see no reason to deny them. (Think for
example: A="People" B="Friend" C="Customer" D="John Smith".)
> > Can you think any (even remotely) good reason to have cycles in
> > member maps
> How about cities as tags and the member map relations representing
> poblic transport connections? Or companies as tags and their mutual
> ownerships as relations. I really do not know who would need
> those. ;) However, you can store and represent meaningfull data that
I've thought those, but as a separate concept to keep meaning of the
member groups more clear. General relations like those could be useful,
but I have no time to implement those yet. Let's talk more about it
after the SQL backend is released.
> > or would anyone be happy if those weren't allowed?
> Did you mean UNhappy?
Yeah, there's a typo. I meant "...or would everyone be happy..." :)
Tuomas Suutari | +358 50 3806983 | thsuut at utu.fi
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